To all those who said the "surge" in U.S. forces in Iraq was doomed to fail, a look at the latest results should be instructive, if not humbling.

Start with American military casualties. For October (36 Americans killed in action), they were the lowest for any month since February 2004, more than three years ago. U.S. casualties have now declined for five consecutive months even as American forces press the fight against al-Qaeda-in-Iraq terrorists and move out of their mega-bases to operate from security outposts in Iraqi neighborhoods. Steadily fewer American soldiers killed or wounded is a measure of a weaker enemy now in retreat - in fact, an enemy being defeated - plus dramatically increasing cooperation from Iraq's civilian population.

This latter point is vital, on both military and political grounds. As security expands and Iraqis consequently feel safer from retaliation by terrorists and sectarian extremists, their willingness to cooperate with U.S. and Iraqi government forces is growing accordingly. A major reason that al-Qaeda-in-Iraq terrorists are now losing is because Iraqi civilians are tipping off coalition forces about the locations of roadside bombs, arms caches and terrorist cells.

Army Lt. Gen. Ray Odierno, deputy to Iraq commander Gen. David Petraeus, gave these totals in a briefing last week for illegal arms, ammunition and explosives recovered in just the last two weeks of October: "Over 37,000 pounds of explosives, a thousand gallons of nitric acid used to make homemade explosives, over 2,000 artillery rounds and over 500 rockets, 136 assembled explosively formed penetrator IEDs (improvised explosive devices), along with 359 copper discs used to make more EFPs, and hundreds of rifles, grenades, anti-tank weapons and suicide vests." Odierno attributed these arms captures largely to tips from local Iraqi civilians.

The death knell for any insurgency or terrorist movement sounds when the civilian population that these killers claim to represent begins turning them in to the security forces.

Next, consider the numbers and trend lines for Iraqi civilian deaths. This is a core indicator not only for moral and humanitarian reasons but because protecting Iraq's civilian population is a central goal of Gen. Petraeus' new counterinsurgency strategy. Iraqi civilian deaths are down more than 60 percent since their peak last December, from 3,000 that month to just over 700 in October. That's still too many, of course, but in a nation of 25 million people beset with sectarian violence and terrorism, a two-thirds drop in civilian deaths is a remarkable achievement.

As with U.S. casualties, the trend line for Iraqi civilian deaths is steadily declining, particularly since the surge offensives aimed at clearing and holding strategic population centers gained momentum this past summer.

Securing greater Baghdad against terrorist attacks is a surge priority. Results? The incidence of mass-casualty terrorist attacks (truck bombs, car bombs and the like) in Iraq's capital city is down 75 percent in recent months.

The second-ranking surge objective was pacifying Anbar province, formerly the heartland of the Sunni insurgency against U.S. forces and their Iraqi government allies. A year ago, Anbar was suffering more than 300 enemy attacks and hostile incidents per week. The number for the last week of October all across Anbar, Iraq's largest province, was fewer than 30.

Overall, the declining numbers of terrorist attacks and security incidents represent, as Gen. Odierno noted, "the longest continuous decline in attacks on record."

Credit for these impressive, even stunning, gains in Iraq is irrefutably attributable, first, to the surge's 30,000 additional U.S. troops and Petraeus' new counterinsurgency strategy. Without these essential reinforcements and a wholly new strategy, the American mission in Iraq would be where it was last December - a failing effort staring at defeat.

Instead, al-Qaeda is on the run and losing, the main Shia militias are respecting a truce with coalition forces, and the Sunni tribal sheiks in Anbar and Diyala provinces and elsewhere have joined U.S. forces against al-Qaeda. Sectarian reconciliation, the ultimate political key to peace and security in Iraq, remains unfulfilled at the national level but is gaining ground locally under U.S. tutelage.

Acceptable levels of security and stability define the road out of Iraq for U.S. combat forces. The surge's success brings that day closer.